When a scope is mounted on a rifle or similar firearm, the mounting of the scope on the firearm must be precise. Various forms of scopes include mounting base portions from which the scope barrels thereof are supported and which may be readily removably supported in a stationary manner from the barrel of an associated firearm. This type of removable mounting of a scope is most desirable and yet presents problems in assuring identical positioning of the scope on the firearm each time it is mounted.
While the removable mounting of a scope base upon a rifle barrel has been developed to the extent that substantially identical repositioning of the scope base may be obtained each time the scope base is mounted on an associated firearm, the scope itself represents a delicate instrument and difficulty has been encountered in providing suitable means for mounting a scope barrel from the scope mount. The barrel of a scope is sensitive to temperature changes and restrained expansion and contraction of the scope barrel can adversely effect the scope optics. The gun barrel upon which the scope base may be mounted is subject to temperature changes and the usual mounting lug provided on a scope can transmit considerable expansion stress forces to the scope barrel upon the barrel of the firearm being heated as a result of the firearm being fired.